Compound lumber



(No Model.)

J. MARIS.

GOMPOUND LUMBER.

4 Patented Apr. 6, 1886.

WITNESSES N. PETERS. Plwmulm mr, Wishingion. D. t:v

STATES PATENT Orricn.

JARED MARIS, OF PHILADELPHIA, PENNSYLVANIA.

COMPOUND LUMBER.

SPECIFICATION forming part of Letters Patent No. 339,199, dated April 6,1886.

Application filed May 15, ISES. Serial No.165,023. (No model.)

To all whom it may concern.-

Beit known that I, JARED lVIARIS, of Philadelphia, in the county ofPhiladelphia and State of Pennsylvania, have invented certain new anduseful Improvements in Methods of Manufacturing Compound Lumber fromwhich Articles or Structures are Formed; and

'I do hereby declare the following to be a full,

clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to an improved method of manufacturing compoundlumber from which articles or structures are formed, the object being tostrengthen or stiffen or lighten such articles or structures andregulate the expansion thereof; and it consists, first, in removingportions of the wood from the piece from which the structure or articleis to be formed and introducing into the recesses or cut-away portionsseparate and independent strips or pieces of wood or material of suchform and character as will serve to strengthen or stiffen or lighten thecompleted article or structure or to regulate the expansion thereof 5second, in removing portions of the wood from the piece from which thestructure or article is to formed and introducing into the recesses orcut-away portions separate and independent strips of wood or material insuch manner that they will break joints one with another; third, inremoving portions of the wood from the piece from which the article orstructure is to be formed and introducing into the recesses or cut-awayportions very thin strips of wood or material, in such a manner thatthey will break joints one with another and allow of the employment of agreat number of re-enforcing or supplemental strips in a comparativelysmall space; fourth, in removing portions of the wood from one side orface of a piece from which the article or structure is to be formed andintroducing into such recesses or cut-away portions separate andindependent strips of wood or material, so as to extend only partlythrough the main piece; fifth, in bending a piece of wood into anydesired form, and then cutting or forming recesses therein andintroducing into said recesses separate and independent strips of woodor material, for strengthening or lightening or regulating the expansionof the completed structure or article; sixth, in certain other featuresof invention in the method of forming structures or articles from wood,as will be hereinafter described, and pointed out in the claims.

In the accompanying drawings, Figure l is a plalrview of a straightpiece of wood having strips of wood inserted therein in accordanee withmy invention. Fig. 2 is alongitudinal section, and Fig. 3 is atransverse section, of the same. Figs. 4, 5, and G are similar views ofa straight piece of wood having strips of wood inserted therein from itsoppo site sides. Fig. 7 is a detached view of one of the strips forinsertion into the piece. Fig. 8 represents a bent strip of wood havingpieces inserted therein from one side. Fig. 9 is a similar view showingthe pieces inserted from opposite sides. Fig. 10 is a cross section of apiece of wood having strips inserted from its sides so as to intersectone another. Fig. 11 is a cross-section of a square piece of wood havingstrips of wood inserted in its sides, and Fig. 12 is a crosssection of around piece of wood with strips of wood inserted in its periphery.

In Figs. 1, 2, and 3, A represents a piece of wood having elongatedslots a formed therein by means of a circular saw or by other means.These slots are preferably made very narrow and extend only partlythrough the piece, so that the side opposite the saw kerfs or slotsremains undisturbed and uncut. The slots are also preferably formed soas to break jointsin the manner shown. \Viihin each slot is inserted athin strip of wood made in the form illustrated in Fig. 7, the curvededge of the strip being cut so as to conform in shape to the bottom ofthe saw-kerf and fit snugly therein. To retain the strips againstdisplacement, they are secured within the slots by means of glue orother cement. By making the saw-kerfs very narrow and insertingcorrespondingly thin strips therein and arranging the latter so as tobreak j oints,as described, I am enabled to materially strengthen thepiece and increase its elasticity without adding to its size or weight.Instead of forming the saw-kerfs in one side only of the piece, they maybe formed in opposite sides thereof, as shown in Figs. 4, 5, and 6, andin some kinds of work this plan may be'the preferred one.

In Fig. 8 I have represented a piece of wood which is bent into anydesired form, after which recesses or slots are formed thereinand thestrips of wood inserted within the recesses.

In Fig. 9 the piece is bent and the stripsinsert-ed into the oppositesides of the piece that is to say, into the concave and the convexsurfaces of the strip.

- in slots extending around the entire circumference of the piece, suchmethodbeing resorted to in articles of sufficient size to admit of theinsertion of the strips on all sides or within the entire periphery ofthe piece of wood of which it is to be formed.

Many important advantages are derived from my improved method ofmanufacturing articles or structures from wood, and of the number thefollowing are enumerated: In such articles or structures as require tobe compact in form and size and of maximum strength the insertion ofthin strips within correspondingly narrow slots in the piece of wood, sothat the strips shall overlap and break joints, enables me to greatlyenhance the strength of the piece, as it allows of the employment of anysuitable kind of wood, and to re-enforce and strengthen it by the thinstrips,which are arranged so as to conform as nearly aspossible to thearrangement of the natural fiber of .the wood, and as the re-enforcingor supplemental strips may consist of very hard, tough, and elasticwood, they serve to add very materially to the strength of the piece sore-enforced. Again, the elasticity of a piece of wood may be greatlyincreased by resorting to my improved process, as a piece of wood havinga limited amount of elasticity, when re-enforced by thin strips of toughand elastic wood inserted therein in the manner described, is renderedexceedingly resilient and strong, and thereby adapted to many uses forwhich it could not be used in its natural state. Again, by inserting-thethin strips of wood within thenarrow slots in such a manner that thegrain of the strips will intersect or be arranged across the grain ofthe piece, the latter will be stiffened. and prevented from cracking orsplitting; also, the expansion and contraction of a piece of wood may beincreased or decreased or equalized by the employment of there-enforcingor supplemental strips.

It is well known that wood expandsin a direction transverse to thelength of its fiber and not in a line therewith. Hence by inserting thethin strips of wood so that the grain of the strips shall be arranged atright angles to the grain of the piece the tendency of the piece toexpand or contract will be in a great measure counteracted by thetendency of the fiber of the strips to expand in an opposite direction.By a proper location and arrangement of the thin strips the expansion ofthe piece of wood may be regulated and controlled as desired.

In many instances a cheap grade of wood may be utilized by properlyre-enforcing its strength or stiffness or elasticity by the employmentof the supplemental strips, as described, and also a structure ofminimum weight may be secured by this process, as it allows of the useof the lightest species of wood, which may be properly strengthened andstiffened throughout its length, or at any point where it may besubjected to heavy strain or weight.

In the manufacture of articles from bent woodthe process described is ofvalue and importance, for the following reasons among others that mightbe cited:

It is well known that the tensile strength of wood exceeds itscollapsing or crushing strength. Thus, for example, when a piece of woodis bent, the fibers on the inside of the curve will fold ontothemselves, while the fibers on the outside of the curve will retaintheir normal position, or nearly so. N ow, when a piece of wood thusbent into curved form is allowed to absorb moisture from an source, thelateral expansion of the folded fibers will tend to lengthen the innerface of the curve, and hence to straighten it. This change of curve is aserious objection in all cases where symmetry or joints are affectedthereby. By inserting the thin strips of wood into the narrow saw-kerfson the inside of the curve, the grain of the strips being arranged inline with the grain of the curved piece, the tensile strength of thestrips is utilized in counteracting the tendency of the crowded fiberson the inside of the curve to expand, and thereby retains the piece inits curved form.

As my improved process is applicable to a great variety of specialpurposes, I do not restrict myself to any particular purpose for whichit may be used.

Having fully described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. A strip or piece of wood having a series of short narrow strips orpieces, substantially as described, secured within short narrow slotsformed with the strip or piece, substantially as and for the purpose setforth.

2. The method of manufacturing compound lumber, consisting, essentially,in forming a series of narrow slots in one or more faces of a piece ofwood and securing withinlsaid slots thin strips or pieces of wood, thesaid thin strips being arranged to break joints with one another.

3. The method of manufacturing articles or structures of bent wood,consisting in first bending the wood into the desired form, and thenforming narrow slots therein and inserting within the slots thin stripsof wood, substantially as set forth.

IIS

4-. A piece of wood provided with narrow 6. A piece of wood havingnarrow semicirslots arranged to break joints one with ancular groovestherein and thin strips of wood other, and thin strips of wood securedwithin semicircular in shape inserted in said grooves. said slots so asto break joints, substantially In testimony whereof I have signed this 5as set ;|:'orth. specification in the presence of two subscrib- I 5 5. Apiece of wood provided with narrow ing witnesses. slots extending partlythrough the piece, and JARED MAR-IS. narrow strips of material securedwithin said \Vitnesses: slots so as to break joints, substantially asset G130. L. MARIs, 1o forth. ARTHUR M. \VARE.

